Collecting statistics on iframe permissions use.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 74b8d3f070387d3ad8c65d18c1b83dfd3a6efb9b..5bca9f484cf5e3185ebeb6b5d392c7a3416f218b 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -28356,6 +28356,25 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Permissions.Requested.CrossOrigin" enum="PermissionStatus">
+  <owner>keenanb@google.com</owner>
+  <owner>jww@chromium.org</owner>
+  <summary>
+    The embedder's permission setting at the time of a cross-origin iframe
+    permission request for a given permission type. See the corresponding
+    histogram suffixes.
+  </summary>
+</histogram>
+
+<histogram name="Permissions.Requested.SameOrigin" enum="PermissionType">

[Alexei Svitkine (slow), 2015/07/09 17:42:03]

Seems like Permissions. is a new top-level prefix. Can you instead find an
existing prefix to nest under?

[keenanb, 2015/07/09 19:33:50]

i was originally planning to use ContentSettings.PermissionRequested, but was
advised and agreed to use Permissions.Requested. It is much more fitting and
would be preferred for future stats collection anyhow.

what drawbacks are there to using a new top-level prefix?

[Alexei Svitkine (slow), 2015/07/09 19:51:03]

How many new histograms will be added with this top-level prefix? The drawbacks
is cluttering top-level categories - i.e. same thing as not to have too many
top-level source directories under src/. But maybe if you are planning to use
this top-level category for a number of future metrics, then this is OK.

+  <owner>keenanb@google.com</owner>
+  <owner>jww@chromium.org</owner>
+  <summary>
+    The permission type (geolocation, and such) of a same-origin permission
+    request.
+  </summary>
+</histogram>
+
 <histogram name="Platform.AsvGroup">
   <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
   <summary>
@@ -64115,6 +64134,12 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="3" label="IGNORED"/>
 </enum>
 
+<enum name="PermissionStatus" type="int">
+  <int value="0" label="PERMISSION_STATUS_GRANTED"/>
+  <int value="1" label="PERMISSION_STATUS_DENIED"/>
+  <int value="2" label="PERMISSION_STATUS_ASK"/>
+</enum>
+
 <enum name="PermissionType" type="int">
   <int value="0" label="PERMISSION_UNKONWN"/>
   <int value="1" label="PERMISSION_MIDI_SYSEX"/>
@@ -73429,7 +73454,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <affected-histogram name="PerformanceMonitor.HighCPU"/>
 </histogram_suffixes>
 
-<histogram_suffixes name="PermissionActions">
+<histogram_suffixes name="PermissionTypes">
   <suffix name="MidiSysEx" label="Midi SysEx permsision actions"/>
   <suffix name="PushMessaging" label="Push messaging permission actions"/>
   <suffix name="Notifications" label="Notification permission actions"/>
@@ -73438,6 +73463,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <affected-histogram name="ContentSettings.PermissionActions"/>
   <affected-histogram name="ContentSettings.PermissionActionsInsecureOrigin"/>
   <affected-histogram name="ContentSettings.PermissionActionsSecureOrigin"/>
+  <affected-histogram name="Permissions.Requested.CrossOrigin"/>
 </histogram_suffixes>
 
 <histogram_suffixes name="PNaClTranslatorTypes" separator=".">